Editing Cherbourg (section)

===Geology===
[[File:Montagne-du-roule.jpg|thumb|right|The Montagne du Roule seen from the commercial harbour.]]
Located at the end of the [[Armorican Massif]], Cherbourg retains traces of the geologic formation, deformed [[granite]]s and [[Metamorphic rock|metamorphic]] [[schist]]s of the [[Precambrian]] of [[Variscan orogeny|Hercynian orogeny]] by the folding of the [[arkose]]s of the [[Cambrian]] and Armorican sandstone and shale of the [[Ordovician]]. These folds result in layers of sandstone tilted 45° towards the north-east on la Fauconniere (including "[[La Roche qui pend]]" ['the hanging rock']) and the {{Interlanguage link|Montagne du Roule|fr}}.<ref>''roule'' is the medieval name of the sandstone</ref> These two cliffs are due to sea erosion in the [[Quaternary]]. The retreat of the sea then gave way to sand dunes and tidal marshes, destroyed by the urbanisation of the 17th and 19th centuries, identical to those of Collignon in Tourlaville.<ref name=pedestre>{{cite web|url=http://www.cuc-cherbourg.fr/Pages/telechargement/telechargement/guide_sentiers_pietons.pdf|title=Sentiers piétons|work={{Interlanguage link|Communauté urbaine de Cherbourg|fr}}|access-date=5 September 2015|archive-url=https://web.archive.org/web/20150923211744/http://www.cuc-cherbourg.fr/Pages/telechargement/telechargement/guide_sentiers_pietons.pdf|archive-date=23 September 2015|url-status=dead|df=dmy-all}}</ref>

These rocks in the soil have been used for centuries in several ways: Crushed granite extracted in [[Querqueville]] and [[arkose]]s of Becquet, have been used for the manufacture of rubble ({{Interlanguage link|moellon|fr}}) and blocks squared for [[lintel]]s. The [[greenschist]], whose colour comes from [[Chlorite group|chlorite]] and [[sericite]], are used mainly for roofing in Nord-Cotentin, but also masonry in Cherbourg. The Armorican [[sandstone]] of the Montagne du Roule is used for rubble and rockfill. Most of the many quarries, which opened in the metropolitan area for building the [[Cherbourg Harbour|harbour wall]], are now closed.<ref name=pedestre />